Field
The present disclosure relates to a ferrite magnetic substance and a method of manufacturing the same.
Description of the Related Art
Due to the depletion of fossil energy and environmental pollution these days, the need to develop techniques for minimizing the use of fossil energy is increasing. Accordingly, environmentally friendly vehicles, such as hybrid vehicles, which are driven by the combination of power of an internal combustion engine and electrical power, and electrical vehicles, which use electrical power, are receiving attention.
Typically, environmentally friendly vehicles are driven by electricity, unlike conventional systems using hydraulic pressure or mechanical force, and the kind and number of motors for use in vehicles are increasing.
Thus, in order to increase the efficiency of vehicles, such as fuel efficiency or the like, an increase in motor efficiency is essentially required. Since the motor efficiency is significantly affected by the magnetic properties of a magnetic substance, a rare earth metal-based magnetic substance having superior magnetic properties has been conventionally utilized.
However, the rare earth metal-based magnetic substance is expensive and thus the motor price is increased, and also, the vehicle manufacturing cost is increased. Furthermore, the supply of magnets is not sufficient.
Hence, magnetic substances that are inexpensive and have superior magnetic properties have been developed recently.
Among such magnetic materials, ferrite is an oxide-based magnetic material composed mainly of iron oxide (Fe2O3), and examples thereof may include soft ferrite, hard ferrite, and semi-hard ferrite, based on the magnetic properties thereof.
Soft ferrite is a soft magnetic substance that exhibits magnetism within a magnetic field, and is featured by low eddy-current loss in the high-frequency-range when compared to metals. Hard ferrite is a kind of permanent magnet, is useful for generating magnetic fields, is typically exemplified by Ba or Sr ferrite, has high magnetic anisotropy, and is inexpensive.
Although semi-hard ferrite is not easily magnetized, once it is magnetized, its state may be maintained, and semi-hard ferrite is thus applicable to memory, tape media, disks, etc. because degaussing thereof is easy.
In particular, a ferrite magnetic substance, which is employed in a ferrite core suitable for a transformer or inductor of an environmentally friendly vehicle, may be manufactured by compressing and then sintering a soft ferrite material, but suffers from relatively large core loss inappropriate for use in a magnetic core, heat generation due to the core loss, and deterioration of magnetic properties.
Moreover, since such a ferrite magnetic substance exhibits high core loss at high temperatures, it is difficult to apply to vehicles, which have to operate under various conditions. It is thus urgently required to develop a ferrite composition that exhibits low core loss at high temperatures to thus be applicable for use in a transformer or inductor of an environmentally friendly vehicle.
The disclosure of this section is to provide background of the invention. Applicant notes that this section may contain information available before this application. However, by providing this section, Applicant does not admit that any information contained in this section constitutes prior art.